Control systems associated with vehicle systems, such as a rail vehicle system including one or more powered units (such as locomotives) and one or more non-powered units, may be used to control an amount or direction of energy transfer between various portions of the vehicle system. The powered units may require energy, for example, to power traction motors to propel the vehicle system. The non-powered units may also require power. Such power may be provided, for example, from a powered unit to one or more non-powered units in a head end power (“HEP”) arrangement. For example, if the non-powered units are used as passenger cars, than power may be required for heating or cooling a passenger car, providing lighting for the passenger car, or outlet power for other passenger necessities or conveniences. Similarly, if the non-powered units are used as cargo cars, such cars may also require power for lighting, refrigeration, or other uses.
The powered units of such a vehicle system may utilize a direct current source, such as a battery that is charged or powered by a prime mover, such as a diesel engine, or a battery that is additionally or alternatively charged by an external energy source. Other power sources may also be used additionally or alternatively. For example, in addition to a battery, the vehicle system may utilize a capacitor for energy storage. Also, energy may be provided by dynamic braking, which also may be used to charge the battery. Further, external charging systems may be used, such as a third rail, catenary, or AC source to which the vehicle system may be connected when at rest, such as a bayside charging station. Further, energy may be transferred between the various power sources. For example, energy may be transferred from a capacitor to a battery.
Vehicle systems, such as rail vehicle systems, may require a considerably large amount of power to perform a given mission. For example, a commuter rail vehicle system that utilizes power supplied from an external source to charge an onboard battery may be required to make a number of trips between multiple destinations before the battery can be recharged. A considerable amount of energy thus may be required to be stored in the battery, resulting in a generally large space being required not just for the battery, but also, for example, for hardware associated with the control and function of the battery. However, space is frequently at a premium on such vehicle systems.
Further still, vehicle systems may also include a number of different energy management systems, each consuming a generally large space on-board the vehicle system. The hardware associated with the control and function of each of the various systems results in an even larger amount of weight onboard the vehicle system, and increases the space consumed on the vehicle system, and increases the expense to procure, operate and maintain the vehicle system.